SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7a2aad366d42a3343147a90446a2c197e67b8b032e305a2d2b0cf5bfa0d8d01' 
  AND token = 'SYiBEzpvpH/WJa7VfsKQCsZpGQLuaOsTNKTuwB3qcA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}